Shrouding of turbine-blades.



A. W..GLARKB.

l sHBoUDING oF TURBINE BLADES.

APPLIUATION FILED MAB.. 5. 1907.

Patented Sept. 13,1910..

Witnesses:

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UNITED STATES PATENT carica,

ATHOL WILFRID CLARKE, or MANCHESTER, ENGLAND, AssIeNORTo 'mit wnsrme- HOUSE MACHINE COMPANY, A CORPORATION or PnNNsYLvANm.

ysisiRoUDINei or nonnina-BLADES.

Speccation of Letters Patent. Patented Sept. V13, 1910.

Application and noma s, 190'?. serial Nc. 360,775.

To all whom it may concern:

'Be it known that I, ATHOL WiLFiiin CLARKE, a `.subject of the Kingl of Great.

provements Relating to the Shrouding of Turbine Blades or Varies, of which the following is a specification.

' Thls invention relates to the shroudiiig of turbine blades or varies where such shrouding consists, as has already been proposed, of a thin metal strip attached to the ends of the blades or varies.

The object of tl'ie invention is to improve' the mode ofLattaching such a strip `to the blades or "vanes so that the labor involved is reduced.

According to this invention'A the free end 0f each of the several blades or varies and the co-actin -face of the sliiouding strip are formed wit one or more locking recesses and projections which are normally complementary one to the other, or ap roxiinately so, and enga ed by temporary istortion of the strip or y permanent mechanical dis-- placement of the metal of the blades or strip. i

In the accompanying drawings, Figure 1 is a sectional elevation showing one inode of engagement by temporarydistortion of the strip, the blade or vane being rovided with a single projection having two ocking faces; Fig. 2 a similar view showing the strip in position and provided with fins or lips; Fig.

3 a sectional elevation at right angles to Fig.

2, showin'gmeans for connectin the ends l of the strip; Fig. 44 a broken p an of the faces 3.

blade and strip shown in Figs. 2 and 3,show ing also means for rendering the fins more pliable; andv Figs. 5 and 6 are sectional elevations showing one mode of engagement by permanent mechanical displacement of the metal of-theblade, the strip being provided ifi'vith a single projection having two locking aces.

Referring to Fig. 1, the free end of the blade or vane 1 is fashioned to a vsuitable hold-fast shape, for .instance by forming notches 2 at opposite corners,`the notches 2 being undercut so as to provide two locking The shrouding stri 4 is provided on the face adjacent to the b ades or varies 1 with counterpart projections 5; the notches acting faces of the projection 9.

2' and yprojections 5 are engaged with each' other by temporarily distorting the shrouding strip 4.in a direction arallcl to its i length, that is to say by bending the strip 4 `er transversely, as shown in the figure, in or that the distance between the projections 5 may be increased to ermit the latter to enter the notches 2, a ter which when' the strip 4' is released to regain its original configuration, projections 5 spring into their iial position, as shown in Fig. 2.

For a greater convenience in effecting the distortion ofthe shrouding strip 4, as well .as to provide aslirouding which 'shall be of a more or less elastic nature, and thus facilitate small-running clearances between the shrouding strip and the cylinder or spindle, as the case may be, the shrouding strip4 may, as shown in'Figs. 2, 3 and 4, be provided with fins or lips 6 disposed at an. angle to the surface of-the strip and extending toward vthe stator or rotor of the turbine, as the case may be, so that in the event of contact being made therebetween, said tins or lips G will yield. The tins or lips 6 can be iiiade more pliable by dividing the same radially at points along the circumference, as for instance by fine saw cuts 7. The ends of the strip 4 or 1of the several sections ofthe strip, if made in more than one piece, may be suitably connected together, as forcxample by overlappingtlie saine, as shown iii Figs. 3 and 4, and coniiectin the ends by means.. of a rivet 8.v Provision may be Iliade for expansive action of the strip if and when required, for instance by elongating the rivet hole in onel of the overlapping ends.

In some cases, iis shown in Figs. 5 and 6, the shrouding strip 4 inay be foi-med with a single undercut or dovetail projection 9 adapted to enter a notch or recess 10 in the respective blade or vano ends. The notches or recesses 10 are not undercut, but are provided at each side with a raised portion or tip 11 adapted to make contact with the coway` upon the application of pressure to the shrouding strip 4, the. metal of the raised portions or tips 11 vcan be mechanically displaced so as to enga e the undercut portions or locking faces o the' projections 9 and hold the strip secure. Obviously in lieu of this hist described form, the locking notch In this or recess 10 might be formed in the shrouding strip 4, and the undercut projection 9 formed fin the ends of the blades 0r Yanes.

What I claim isz l. In combination. with the vblades or varies of an elastic tuid turbine, a shroud I' for the outer or tree ends of' said blades or vanes, a. longitudinally extending projection formed integrally with said shroud and meansI secured to each blade or vane,.,fcr securing` said shroud in place by 'being distorted to' grip said projection. A

2. In combination with the blades or vanes of an elastic iiuid turbine, va shroud for the outer or .tree ends of said blhdes or varies, a longitudinally extending dove-tail projection on said shroud, a notch in the outer or vtree end of each blade or vane adapted to t receive said projection and means carried by each blade or vane, for securing said shroud in place by being permanently set to grip said projection.

3. In combination with the -blades or vanes of an elastic tluid turbine, a Shroud for the outer or tree ends of said blades or projection vanes, a longitudinally extending dove-tail on said shroud, a notch in the outer or free end of each blade or vane adapted to receive said projection and tips, adapted .to grip Said projection and secure said shroud in place by being permanently distorted'.

,4. In combination with the blades or Yanes of an elastic Huid turbine, a shroud for the outer or free ends of said blades or Yanes, a. longitudinally .extending` dove-tail projection on said shroud, a notch in the outer or free end oi each blade or vane adapted to receive said projection and means, carried by each `blade or vane, for

' securing said shroud in place by being per- .manently distorted.

In testimony whereof, I have hereunto subscribed my name this 21st day of l`eb-l lruary 1907.4

ATHOL WILFRID CLARKE.

Witnesses:

JAs. STEWART BnoADroo'r, PERCY IVivL H oL'r. 

